1. Field of the Invention
The present invention relates to a water saving device for a reverse osmosis water fountain machine, and more particularly to a water saving device attached on the drain pipe of a reverse osmosis water fountain machine so that the waste water drained out can be recycled for saving water resources and reducing waste.
2. Prior Art
Water from a water pipe contains a small quantity of pollutants, so that drinking the water over a long time period can result in some diseases. Hence, drinking water purification is very indispensable. Purifying drinking water has become an important matter. The methods traditionally taken include reverse osmosis, ion-exchange, distillation, activated carbon filter, sedimentation-type filter, boiling, ozone sterilization and ultraviolet ray sterilization, etc. Among them, reverse osmosis is the most popular because that method can obtain the cleanest water.
The conventional revers osmosis water fountain machine, as shown in FIG. 6, comprises two cartridge filters A and B, a pump C, a reverse osmosis cylinder D, an activated carbon filter cylinder E, a water tank F and a faucet G, cooperating with some pipes connecting them into system to process raw water with four purifying treatments in order to obtain the cleanest drinking water. The treating procedures includes:
1. pre-treatment: in the first cartridge filter A, the strainer core with 5 (micrometer) meshes inside will filter the macro-crystalline impurity substance for prolonging the service life of the reverse osmosis membrane; PA1 2. mid-treatment: the activated carbon filter B filters the impurity substance further, and prolongs the service life of the reverse osmosis cylinder; PA1 3. reverse osmosis treatment: in the reverse osmosis cylinder D, the semi-permeable membrane (special-cellular membrane) filters the micro-crystalline impurity substance to obtain cleaned and purified water to be drained into the water tank F for drinking; PA1 4. post-treatment: by means of the activated carbon filter cylinder E, the pure water is treated by high-attenuating compressed granular activated carbon, so that the treated water can be drained to the faucet G for drinking.
Taking advantage of the above-mentioned purification system, a high-purity drinking water is available. But, we find that a great deal of waste water is drained from the reverse osmosis cylinder D, causing a tremendous waste. As an example, to obtain one glass of pure drinking water, five glasses of raw water are required for processing, with four glasses of water becoming waste water. Take for instance that one person should drink 8 glasses of water (500 CC) in one day, with respect to the above-mentioned purification system, 16 kg of water is generated in a day. We can find a proliferation of poor purification systems that waste a large amount of water. Today, the preservation of water resources is desired, and methods for using the 4/5 glasses of drained water, to achieve a high purification level, has become a vital task. With more than 500,000 reverse osmosis fountain machines, and the number is increasing rapidly, the quantity of the waste water will exceed that of the storage of the sum of two large reservoirs, per year. Furthermore, according to the World Bank, the twenty-first century will be "The war of Water", indicating that lack of water resources are critical. Therefore, the World Bank is urging Countries to conserve water efficiently. The most sophisticated and popular technical method of processing drinking water is reverse osmosis (RO). The shortcoming of reverse osmosis is that in order to obtain high quality drinking water, a large quantity of water will be wasted which could otherwise ease the drought situation in many areas of the world.